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-rw-r--r--lib/fixunssfsi.c43
1 files changed, 43 insertions, 0 deletions
diff --git a/lib/fixunssfsi.c b/lib/fixunssfsi.c
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+/* ===-- fixunssfsi.c - Implement __fixunssfsi -----------------------------===
+ *
+ * The LLVM Compiler Infrastructure
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+ * ===----------------------------------------------------------------------===
+ *
+ * This file implements __fixunssfsi for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#include "int_lib.h"
+
+/* Returns: convert a to a unsigned int, rounding toward zero.
+ * Negative values all become zero.
+ */
+
+/* Assumption: float is a IEEE 32 bit floating point type
+ * su_int is a 32 bit integral type
+ * value in float is representable in su_int or is negative
+ * (no range checking performed)
+ */
+
+/* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */
+
+su_int
+__fixunssfsi(float a)
+{
+ float_bits fb;
+ fb.f = a;
+ int e = ((fb.u & 0x7F800000) >> 23) - 127;
+ if (e < 0 || (fb.u & 0x80000000))
+ return 0;
+ su_int r = (fb.u & 0x007FFFFF) | 0x00800000;
+ if (e > 23)
+ r <<= (e - 23);
+ else
+ r >>= (23 - e);
+ return r;
+}